adc.c

基于s3c44b0的rtc,watchdog,adc,ads的驱动程序

#include <linux/config.h>
#include <linux/utsname.h>
#include <linux/kernel.h>
#include <linux/major.h>
#include <linux/string.h>
#include <linux/fcntl.h>
#include <linux/timer.h>
#include <linux/sched.h>
#include <linux/tty.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/miscdevice.h>
#include <linux/delay.h>
#include <linux/types.h>
#include <linux/miscdevice.h>
#include <linux/ioport.h>
#include <linux/mc146818rtc.h>
#include <linux/poll.h>
#include <linux/proc_fs.h>
#include <linux/spinlock.h>
#include <linux/sysctl.h>
#include <linux/pci.h>

#include <asm/mach/irq.h>
#include <asm/hardware.h>
#include <asm/io.h>
#include <asm/irq.h>
#include <asm/system.h>
#include <asm/uaccess.h>
#include <asm/arch/io.h>
#include "44b.h"

#define DEVICE_NAME	"adc"
#define MCLK 64000000

typedef struct {
	int  a0;
	int  a1;
	int  a2;
	int  a3;
	int  a4;
	int  a5;
	int  a6;
	int  a7;
}ADCDATA;

static ADCDATA adcdata;

static int delayLoopCount=400;

void Delay(int);
void Test_Adc(void);
int ReadAdc(int);

int ReadAdc(int ch)
{
    int i;
    static int prevCh=-1;

    if(prevCh!=ch)
    {
    	rADCCON=0x0 | (ch<<2);	//设置采样通道
    	for(i=0;i<150;i++);	
    }

    rADCCON=0x1 | (ch<<2);	//启动A/D转换
    while(rADCCON &0x1);			
    while(!(rADCCON & 0x40));	//A/D转换是否结束

    for(i=0;i<rADCPSR;i++); 
    prevCh=ch;
    return rADCDAT;
}
void Test_Adc(void)
{
    rCLKCON=0x7ff8;		//时钟控制寄存器,使能MCLK作为ADC的时钟电源
    rADCCON=0x1 | (0<<2);	//启动A/D转换
    Delay(100);	

    rADCPSR=255;		//设置预分频值
    
    adcdata.a0=ReadAdc(0);		//分别读取转换后的数字量
    adcdata.a1=ReadAdc(1);
    adcdata.a2=ReadAdc(2);
    adcdata.a3=ReadAdc(3);
    adcdata.a4=ReadAdc(4);
    adcdata.a5=ReadAdc(5);
    adcdata.a6=ReadAdc(6);
    adcdata.a7=ReadAdc(7);
    //	printk("%d,%d,%d,%d,%d,%d,%d,%d\n",adcdata.a0,adcdata.a1,adcdata.a2,adcdata.a3,adcdata.a4,adcdata.a5,adcdata.a6,adcdata.a7);

}
static int adc_open(struct inode *inode, struct file *filp)
{
	return 0;
}
static int adc_release(struct inode *inode, struct file *filp)
{
  	return 0;
}
static int adc_ioctl(struct inode *inode, struct file *file, unsigned int cmd, unsigned long arg)
{
	switch(cmd) 
	{
		case 0:
			Test_Adc();
			return 0;
        	default:
                        printk("ERROR\n");
    	}
    	return 0;
}
static int adc_read(struct file *fp, char *buf, size_t count)
{
    put_user(adcdata.a0, (int *)buf);
    put_user(adcdata.a1, (int *)(buf+4));
    put_user(adcdata.a2, (int *)(buf+8));
    put_user(adcdata.a3, (int *)(buf+12));
    put_user(adcdata.a4, (int *)(buf+16));
    put_user(adcdata.a5, (int *)(buf+20));
    put_user(adcdata.a6, (int *)(buf+24));
    put_user(adcdata.a7, (int *)(buf+28));

    return count;
}
static struct file_operations adc_fops = {
  	open:	adc_open,
	ioctl:	adc_ioctl,
  	release:	adc_release,
	read:	adc_read,
};
int adc_init(void)
{
	int ret;

	ret = register_chrdev(252, DEVICE_NAME, &adc_fops);
	if (ret < 0) {
		printk(DEVICE_NAME " can't get major number\n");
		return ret;
	}
	else 
		printk("OK\n");	

	return 0;
}